[gtk/wip/baedert/for-master] gtk4-demo: Add missing margin-bottom

[Timm Bäder <baedert src gnome org>]

commit 03667a3495c7b765a63d882729c1786ea9c3a3af
Author: Timm Bäder <mail baedert org>
Date:   Sun Oct 11 20:11:39 2020 +0200

    gtk4-demo: Add missing margin-bottom
    
    This was setting margin-end twice

 demos/gtk-demo/shortcuts.ui | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/demos/gtk-demo/shortcuts.ui b/demos/gtk-demo/shortcuts.ui
index 36eda142bd..1de5855966 100644
--- a/demos/gtk-demo/shortcuts.ui
+++ b/demos/gtk-demo/shortcuts.ui
@@ -8,7 +8,7 @@
         <property name="margin-start">50</property>
         <property name="margin-end">50</property>
         <property name="margin-top">50</property>
-        <property name="margin-end">50</property>
+        <property name="margin-bottom">50</property>
         <property name="spacing">10</property>
         <child>
           <object class="GtkButton">